The present invention relates to a driver IC that performs display driving and non-display driving of a display panel, and more particularly to a driving control technology performed when returning to a display from a non-display, for example, a technology which is effectively applied to the driver IC that controls driving of a liquid crystal panel in which a touch panel is incorporated in an in-cell form.
A touch panel is frequently used in a user interface of a portable information terminal such as a tablet terminal or a smartphone, and a panel module for mobile phone in the related art has mainly used an on-cell method by which a display panel and the touch panel are separately configured, but recently an in-cell method by which the display panel and the touch panel, which can be thin, are integrally configured has become popular. In particular, in the in-cell method by which the panel module can be thin, the display panel and a touch sensor share a circuit, and thus, in order to realize a great SN ratio (high sensing SN ratio) with respect to a touch detection signal, it is preferable that sensing be performed during a non-display driving period in which display driving is not performed. In view of an improvement of the sensing SN ratio, the panel module manufactured by the on-cell method is the same as that manufactured by the in-cell method, although the display panel and the touch sensor do not share the circuit, there is an influence of noise due to capacitive coupling.
In JP-A-2012-059265, it is described that a display driver which drives a liquid crystal display panel performs driving by time-dividing a display area, the display driving and touch detection performed by the touch panel can be alternately performed, and detection noise occurring when a touch detection operation is performed is reduced. That is, one frame is divided into a display mode and a touch sensing mode, and a gate driver, a data driver and a touch controller are controlled by a timing controller so as to alternately perform both modes. This system intermittently performs an image display for every several lines, and performs touch sensing during a period when an image output from the display driver is stopped, thereby realizing a high touch detection accuracy.